JPH0124918Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a chiyoke coil that is coupled between various signal lines and ground in electronic devices and the like, and which attenuates interference voltages mixed in from the outside.

Conventionally, in order to attenuate the interference voltage called common mode noise that connects between the signal line and the ground and mixes into the signal line from the outside, magnetic cores such as toroidal cores, EI type cores, pot cores, etc. are used as magnetic cores.
A chiyoke coil is used in which the signal line is directly common-wound. In addition, for those mounted on a board, a chiyoke coil is used, which is a combination of a plurality of small toroidal coils each having a winding wire wound around a toroidal core. In order to attenuate the disturbance voltage, the number of turns must be increased to increase the inductance value and the Q value due to resonance must be decreased. However, conventional winding coils have disadvantages in that the number of turns cannot be increased, and therefore the inductance value cannot be increased, and automatic winding is difficult.

The object of the present invention is to eliminate such drawbacks of the conventional coil coils and to improve the workability of a compact chiyoke coil having a large inductance value so as to enable automatic winding.

The present invention includes a chip body integrally formed with a plurality of magnetic cores made of a magnetic material, each having a cylindrical magnetic core on its surface, and a plurality of magnetic cores having an annular groove and a plurality of lead wire grooves around the magnetic core. This is a dip-type chain coil made by inserting annular coils into each of the annular grooves of the chip body into a magnetic chip consisting of a magnetic cover made of a magnetic material that covers the surface of the chip body.

As shown in FIG. 1, an embodiment of the chiyoke coil of the present invention includes a cylindrical magnetic core 6 in a magnetic body, an annular groove 7 in which an annular coil 4 is inserted around the cylindrical magnetic core 6, and a coil 4.
A chip body 2 is formed by integrating a plurality of magnetic cores provided with lead wire grooves 8 for drawing out lead wires. Therefore, the chip body 2 has a configuration in which a plurality of magnetic cores each having an annular groove 7 into which a coil 4 can be inserted and a cylindrical magnetic core 6 are connected, and the outer surface is finished into a substantially rectangular shape. Here, a coil 4 made of polyurethane-coated copper wire or the like wound twice in an annular shape using an automatic winding machine is inserted into the annular groove 7, the lead wire is pulled out through the lead wire groove 8, and the magnetic material is A chiyoke coil is obtained by covering with a magnetic lid 3 made of the following. Furthermore, it is housed in a case 1 made of an insulating material with a plurality of terminals 5 buried in the bottom as shown in FIG.

The dip type choke coil constructed in this way has an electrical equivalent circuit as shown in Figure 2. If permalloy, amorphous, etc. are used as the magnetic material, the effective permeability can be increased, and the Q value at resonance can be increased due to the large loss. It becomes a small chiyoke coil.

For example, when this type of choke is used as a common mode choke, no impedance is inserted into the line, but it acts as a large impedance against signals that are generally noise that are added between the line and the ground. This type of chiyoke coil prevents equipment from malfunctioning or being destroyed due to noise induced in the line. When a chiyoke coil with a high Q value is used, there is a danger that the intrusion noise will be amplified at the resonant frequency due to the resonance phenomenon of the chiyoke coil itself. This phenomenon can be reduced by suppressing the resonance of the impedance of the chiyoke coil, and lowering the Q value at the time of resonance.

As described above, according to the present invention, a plurality of magnetic cores can be constructed from one magnetic chip, and the coil 4 is manufactured in an annular shape using an automatic winding machine, so that the number of turns and the inductance value can be adjusted. Compared to the conventional toroidal type, the number of coils can be increased, and a small and easy-to-mount chiyoke coil with excellent workability can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an embodiment of the dip type choke coil of the present invention, a is a longitudinal cross-sectional view thereof, b is a cross-sectional plan view taken along line A-A at a, and c is a cross-sectional view taken along line B-B' at a. 2 and 2 are electrical equivalent circuit diagrams of the dip type choke coil according to the present invention. In the figure, 1: case, 2: chip body, 3: magnetic cover, 4: coil, 5: terminal, 6: magnetic core, 7: annular groove, 8: lead wire groove.

Claims (1)

[Scope of utility model registration request] A chip body integrally formed with a plurality of magnetic cores having a cylindrical magnetic core on the surface, an annular groove around the core, and a lead wire groove for a plurality of lead wires; A dip type toothed coil is formed by inserting annular coils into the annular grooves of a magnetic chip consisting of a magnetic cover made of a magnetic material covering the surface of the chip body.